Wire stripping and wrapping gun

ABSTRACT

The driving mechanism for a wire stripping and wrapping tool is positioned along a central axis. Axial movement of a wrapper pin causes a knife to cut, strip and position the wire for wrapping. Different types of insulation can be accommodated.

United States Patent Staiger et al.

[151 3,656,218 [451 Apr. 18, 1972 WIRE STRIPPING AND WRAPPING GUN inventors: Bruno Staiger, Erligheim; Siegfried Schlag, Wimsheim; Walter l-lartl, Winnenden, all of Germany Assignee: International Standard Electric Corporation, New York, N.Y.

Filed: Aug. 21, 1969 Appl. No.: 851,847

Foreign Application Priority Data Aug. 30, i968 Germany ..P 17 90 044.6

US. Cl ..29/33 F Int. Cl. ..B2 1f 15/00 Field ofSearch ..140/ll8,1l9, 122,124;

29/203 H, 203 HM, 33.5, 33.51, 33.10

[56] References Cited UNITED STATES PATENTS 2,743,502 5/1956 Reck ..140/122 X 2,743,503 5/1956 Mallina ..29/33.5l 2,884,685 5/1959 Bas et al. ..29/33.5l 3,023,484 3/1962 Arens et al ..29/203 l-l Primary Examiner-Granville Y. Custer, Jr.

Attorney-C. Cornell Remsen, .lr., Walter J. Baum, Percy P. Lantzy, Philip M. Bolton, Isidore Togut and Charles L. Johnson, Jr.

[5 7] ABSTRACT The driving mechanism for a wire stripping and wrapping tool is positioned along a central axis. Axial movement of a wrapper pin causes a knife to cut, strip and position the wire for wrapping. Different types of insulation can be accommodated.

6 Claims, 8 Drawing Figures PATENTEDAPR 18 I972 SHEET 1 0F 5 INVENTORS BRUNO STA/Q61? s/sqm/so SCI/LAG WALTER HART-1..

BY ATTORN PATENTEDAPR 18 I972 SHEET 3 0F 5 INVENTORS BRUNO STA/G61? .S'IECFR/ED SCHLAC wALree f/ARTL ATI'ORNEY PATENTEDAPR 18 I972 SHEET t [1F 5 mvmoRs a/awvo smlquz susgpmso scHLAq WALTER HARTL F V E ATTORNEY PATENTEDAPR 18 I972 SHEET 5 [IF 5 mvmons BRUNO STA/GER SIEGFR/ED s c/ mq WAL TER HAR n.

ATTORNEY WIRE STRIPPING AND WRAPPING GUN BACKGROUND OF THE INVENTION 2. Field of the Invention The present invention relates to a wire stripping and wrapping gun or tool for cutting and stripping wires, as well as for making wire-wrap joints.

2. Description of the Prior Art Numerous individual tools and devices are known with which wires can be cut to the respective length, and with which the ends of insulated wires can be freed from their insu- Y lation. Devices are also known for producing wire-wrap joints only with wire having a predetermined diameter.

SUMMARY OF THE INVENTION The present invention relates to a wire stripping and wrapping tool which permits processing wires having different manufacturing tolerances for hardness and bond strength of the insulation.

This is accomplished by a centrally arranged drive for the wrapping and pneumatic stripping movement. The wrapping sleeve includes a lever knife having a cutting edge which is lowered upon the wire during axial movement of a wrapping pin, with the bridge of the wrapping pin being simultaneously positioned therebelow. This causes tearing of the insulation on both sides, with the wire being stripped by further relative axial movement and threaded into the wire-wrap portion.

In one embodiment of the invention, a flat spiral spring is used to return the wrapping sleeve to normal.

In a further embodiment of the invention two triggers are positioned one inside the other for operation by one finger.

A still further embodiment of the invention includes an attached cutting device which permits the wire to be led directly from a wire spool along the stripping and wrapping gun, and

i cut to the desired length.

In addition, two valves which are acted upon positively, are attached to the housing.

The present embodiment of a wire stripping and wrapping gun has the advantage that a considerable amount of manufacturing time can be saved. Wires having different values of hardness and bond strength of insulation can be accommodated. The wire stripping and wrapping gun, moreover, has a very simple manner of operation.

The invention will now be described with reference to the accompanying drawings, in which:

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 schematically shows a wire stripping and wrapping gun, partly in a sectional view and with some portions removed to show the lever knife;

FIG. 2 shows the wire stripping and wrapping gun according to FIG. 1 in a top and partly sectional view;

FIG. 3 shows the front portion of the tool according to FIGS. 1 and 2 in a diagrammatic representation;

FIG. 3a shows a cross-sectional view of a spring, taken at section AA of FIG. 1, which biases a wrapper sleeve in a normal position; and

FIGS. 4 to 7 show the sequence of operation.

DESCRIPTION OF THE PREFERRED EMBODIMENT FIGS. 1 and 2 show the tool which is of a gun-shaped design. In the horizontal shaft of the wire stripping and wrapping gun 1 there is a suitable air motor, shown as block 2, which provides the wrapping movement, as well as a clutch, sections 30 and 3b, gearing 4, and a piston 5 which is acted upon pneumatically to provide the stripping movement, all of which are centrally positioned within a housing 6. Inside handle 7 are two triggers 8, one inside the other in the direction of operation, for triggering the electropneumatic control function. The trigger 8a which provides the preferred switching function, extends some millimeters with respect to the other trigger. As indicated schematically, trigger 8a triggers valve a supplying compressed air from line c to valves 22 which supply piston 5. Trigger 8b actuates contact b electrically connected to line e to supply air from line d to air motor 2 via valves 22. In order to require only a small number of end keys, hoses and electromagnetic valves, two air pulse valves 22 which are acted upon positively, are attached to the housing 6. A cutting device 9 with a lever 24 and a limit stop 10 are arranged on the housing 6 in parallel relation to the horizontal axis.

The wire stripping mechanism which is accommodated in the front portion of the tool, consists substantially of three parts, the wrapper sleeve 11 of the wrapper pin 12, and of the lever knife 13, as shown in FIG. 3. The forward pointed end of the wrapper pin 12 is designed as conventional types of tools. However, the continuing slot in which the conductor of the wire comes to lie is not shown.

Both the wrapper pin 12 and the wrapper sleeve 11 are firmly connected to one side of the clutch 30, whereas the other side of the clutch 3b is connected to the gearing 4 and the air motor 2. In the normal position, the two halves of the clutch are disengaged from one another. When the air motor 2 is supplied with air, the side of the clutch 3b facing the air motor 2, likewise receives air via a supply line. During this process, the clutch half 3b as acted upon by the air, moves towards the other half of the clutch 3a, thus transferring the torque thereto.

When interrupting the air supply to the air motor 2, the half of the clutch 3b acted upon by the air, will no longer receive air and thus disengages from the other half with the aid of a spring. During this process there is no guarantee of the starting or normal position of the wrapper sleeve 11 which is an important prerequisite for optimum utilization of the wire stripping and wrapping gun I. As shown in FIG. 3a, in order to obtain an exactly defined zero or normal position, a flat type spiral spring shown as block 23 has one end hooked on the wrapper sleeve 11, with the other end sliding on housing 6, the spring being wound up and tensioned during the wrapping process. Upon termination of the wrapping process, and after the clutch 3 has disengaged, the tensioned flat type spiral spring 23 will eflect an opposite torque, and will then turn the wrapper sleeve 11 against the limit stop 10 and back to normal. The tool is so constructed that important parts, such as the handle with the built-in control elements, as well as pneumatic valves, can be easily replaced in accordance with the building-block principle, by parts or components serving other switching functions. Moreover, it is possible to attach additional elements, such as for electrical digital indication, and control lamps for numerically controlled wiring systems.

The following is a description, with reference to FIGS. 4 to 7, of the threading and stripping operation. The wrapper pin 12 is arranged inside the wrapper sleeve 11 in an axially displaceable manner. The position of the wrapper sleeve 11 in relation to the wrapper pin 12 is fixed by a suitable coupling pin which is retained in the wrapper sleeve 11 and projects into the slot of the wrapper pin 12. A surface 14 is ground on wrapper pin 12 down to the bottom of the notch. The narrow remaining portion 15 of about 0.5 mm .at the point or forward end of the wrapper pin 12 serves to secure the inserted wire 20 to that it cannot be pulled out during the stripping process. At the other end of the wrapper pin 12, the diameter thereof is changed within a 45 transition 16, to a larger diameter.

The wire, coming from a wire spool 21, is led through a slot 17 and an oblong hole 18 in the wrapper sleeve 11 and through a recess in lever knife 13 against the limit stop 10 (FIG. 2).

In FIG. 5 the wrapper pin 12 is shown to be pushed forward by pneumatic action. In the course of the axial displacement, the rear portion of the lever knife 13, which is secured in position inside the wrapper sleeve 11 by a pin 19, is lifted by the transition section 16, thus initiating the stripping process. The cutting edge 25 of the lever knife 13 is lowered and, in cooperation with the portion 15, cuts the insulation of the wire on both sides.

FIG. 6 shows the further course of the stripping process. In FIG. 7 the process is completed, and the wrapping process can be initiated.

The following will describe the application of a wire-wrap joint to a terminal with the aid of the wire stripping and wrapping gun. The wire stripping and wrapping gun I is held in the right hand of the operator. With the left hand the wire 20 is led through the wrapper sleeve 11 against a limit stop 10. By actuating the first trigger 8a the wrapper pin 12 is pushed forward by the pneumatic piston 5. This causes the wire 20 to be stripped and threaded.

Now the wire stripping and wrapping gun I is placed on the terminal to receive the wrapped wire. By further actuating the first trigger 8a and actuating the second trigger 8b both the clutch 3 and the air motor 2 are acted upon by air. In this way a connection is made between the air motor 2 and the wrapper pin, and the rotation of the air motor 2 is transferred to the wrapper pin 12, thus causing the wrapping process to be performed.

By releasing the two triggers 8 the motor is switched off and the wire stripping and wrapping gun I is returned to normal. The wire 20 is then led with the left hand along shaft 40 through a groove in knife 44 of the cutting device 9 as attached to the gun, and to the next terminal, and is cut to the respective length by actuating the cutting device 9 with the aid of the lever 24, by the action of the thumb of the right hand. Downward movement of lever 24 turns a shaft 40, supported in block 41 and knife holder 42, causing knife 44 to rotate and cut wire 20. A spring 45 returns the device to the normal position. The process is then repeated as previously described.

What is claimed is:

l. A tool for cutting, stripping and wrapping wires comprising, first drive means for a wire wrapping movement and second drive means for a wire insulation stripping movement positioned along a central axis of said tool, a wrapper sleeve coupled for rotary movement to said first drive means, a wrapper pin disposed in said sleeve for axial movement by said second drive means, a lever knife pivotally mounted on said sleeve and having a cutting edge disposed at the forward end to contact the wire insulation upon axial displacement of the wrapper pin, a projection on the other end of said knife in sliding engagement with said pin, and means on said pin to engage said projection and pivot said cutting edge, said axial movement of said pin stripping and positioning the wire for a wrapping movement.

2. The device of claim 1 including a flat type spiral spring disposed along said axis around said sleeve and having one end coupled to said sleeve to return said sleeve to a normal position after the wrapping movement.

3. The device of claim 1 including manually operable actuating means positioned one inside the other for operation of said first and second drive means by one finger.

4. The device of claim 1 including cutting means attached to an outer surface of said tool for cutting wire inserted into said tool to a desired length.

5. The device of claim 1 including air control means for actuating said first and second drive means.

6. The device of claim 1 wherein said pin includes an extending portion positioned at the forward end between said pin and sleeve below said wire opposite said cutting edge to cooperate with said edge and tear the wire insulation from both sides, and the other end of said pin having a portion of increasing diameter over that of the forward end to pivot said knife cutting edge. 

1. A tool for cutting, stripping and wrapping wires comprising, first drive means for a wire wrapping movement and second drive means for a wire insulation stripping movement positioned along a central axis of said tool, a wrapper sleeve coupled for rotary movement to said first drive means, a wrapper pin disposed in said sleeve for axial movement by said second drive means, a lever knife pivotally mounted on said sleeve and having a cutting edge disposed at the forward end to contact the wire insulation upon axial displacement of the wrapper pin, a projection on the other end of said knife in sliding engaGement with said pin, and means on said pin to engage said projection and pivot said cutting edge, said axial movement of said pin stripping and positioning the wire for a wrapping movement.
 2. The device of claim 1 including a flat type spiral spring disposed along said axis around said sleeve and having one end coupled to said sleeve to return said sleeve to a normal position after the wrapping movement.
 3. The device of claim 1 including manually operable actuating means positioned one inside the other for operation of said first and second drive means by one finger.
 4. The device of claim 1 including cutting means attached to an outer surface of said tool for cutting wire inserted into said tool to a desired length.
 5. The device of claim 1 including air control means for actuating said first and second drive means.
 6. The device of claim 1 wherein said pin includes an extending portion positioned at the forward end between said pin and sleeve below said wire opposite said cutting edge to cooperate with said edge and tear the wire insulation from both sides, and the other end of said pin having a portion of increasing diameter over that of the forward end to pivot said knife cutting edge. 